The invention relates to an instrument for the correct positional installation of a guide wire for a drilling tool in a bone.
Initial installation of a guide wire into the point of insertion is well-known for the opening of the point of insertion of a femoral nail, for example, for proximal installation. Then the bone is opened using a drilling tool threaded over the wire. An advantage of this method resides in the fact that prior to the actual drilling using a relatively large diameter, the precise position and orientation of the guide wire and, accordingly, also the subsequent bore hole can be checked with the aid of an X-ray device.
It is also well-known to initially pass a tissue protective sleeve over the guide wire, until it is in contact with the bone, in order to avoid soft tissue injury caused by the drilling tool. It is further well-known, to close the tissue protection sleeve using a trocar, in order to improve passage through the soft tissues. Subsequently, prior to the drilling operation, the trocar is removed.
U.S. Pat. No. 5,951,561 discloses a trocar having a plurality of axially parallel bores. The trocar is rotationally engaged in the tissue protection sleeve. If, at the time of X-ray inspection, it is found, for example, that the central bore is situated offset laterally to the desired position in the trocar, a second guide wire is installed in another suitable bore hole. If the second wire is positioned at the desired location, the first wire is removed and drilling is operated over the second wire.